Plasma lactate measurements in healthy cats

Viscoelastic coagulation monitoring parameters in cats with acute arterial thromboembolism

BACKGROUND

Hypercoagulability has been documented in cats with cardiac disease. However, hemostatic parameters, including viscoelastic coagulation monitoring (VCM) have not been reported in cats with arterial thromboembolism (ATE).

HYPOTHESIS/OBJECTIVES

Compare VCM parameters in cats with acute cardiogenic ATE and in control cats.

ANIMALS

Sixteen cats with ATE and 30 control cats.

METHODS

Multicenter university-based prospective study. Cardiogenic ATE was diagnosed based on physical examination and by ultrasonographically-diagnosed left atrial enlargement. Viscoelastic coagulation monitor analysis, CBC, serum biochemistry profile and coagulation profile were performed at admission in cats with ATE. Analysis from healthy control cats was performed using blood collected by direct venipuncture. Our objective was comparison of VCM parameters clot time (CT), clot formation time (CFT), alpha angle (Angle), maximum clot formation (MCF), amplitude at 10 and 20 minutes (A10 and A20, respectively) and clot lysis index at 30 and 45 minutes (LI30 and LI45, respectively) between ATE and control cats.

RESULTS

Cats with ATE had a decreased angle compared to control cats, with a median (range) of 43° (30-48°) compared to 47° (14-59°; P = .01). The parameters A10, A20 and MCF were decreased in ATE cats compared to control cats with a median (range) of 19 units (8-32) compared to 22 units (6-38), 24.5 units (11-40) compared to 29 units (10-47) and 29.5 units (13-44) compared to 33.5 units (14-53), respectively (P = .01, .01 and .01, respectively). The parameters CT, CFT, LI30 and LI45 were similar between groups (P = .22, .09, .62 and .34, respectively).

CONCLUSIONS AND CLINICAL IMPORTANCE

Cats with cardiogenic ATE cats have VCM parameters consistent with hypocoagulability compared with healthy cats.

Case report: Evaluation of hindlimb ischemia using 18F-fluorodeoxyglucose positron emission tomography in a cat with cardiogenic arterial thromboembolism

A 12-year-old castrated male domestic shorthair cat weighing 6.7 kg presented with acute hindlimb paralysis and tachypnea. The femoral pulse was absent bilaterally. Thoracic radiography showed finding compatible with cardiogenic pulmonary edema. Echocardiography revealed hypertrophic cardiomyopathy phenotype and a spontaneous echocardiographic contrast in the left atrium, suggesting cardiogenic arterial thromboembolism. Oxygen supplementation, diuretics, and antithrombotic and thrombolytic agents were also administered. However, hindlimb motor function was not restored. Severely increased aspartate aminotransferase and creatinine phosphokinase, as well as neutropenia with a degenerative left shift were identified, and amputation was considered to prevent sepsis caused by necrosis of the ischemic tissues. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography was performed to evaluate the metabolic activity of the muscle tissues and determine the level of amputation. There was no 18F-FDG uptake in the extremities of either the hind limbs or the caudal parts of the bilateral femoral muscle mass, suggesting a loss of metabolic activity in the area. Considering the wide affected area, a decreased quality of life was predicted postoperatively, and the cat was euthanized at the owner's request. Postmortem muscle biopsy confirmed weak atrophy of the left femoral muscle and prominent atrophy of the right calf. This case report describes the use of 18F-FDG PET in a cat with ischemia caused by cardiogenic arterial thromboembolism.

Use of pupillometry for the evaluation of analgesia in dogs hospitalized in intensive care: A prospective study

A prospective study was performed on hospitalized conscious dogs. The objectives were: 1) to evaluate the feasibility and reliability of portable infrared pupillometry using a measure of photo light reflexes, 2) to identify parameters influencing measures, and 3) to compare parameters before and after the administration of analgesia. Twenty-nine dogs were included. Pupillometry was feasible by a single person. There was an excellent reliability for the evaluation of pupil diameter. There was poor to good reliability for the other parameters. There was an association between weight and mean pupil diameter (estimate = 0.1 mm, CI95 = [0.0; 0.1], P = 0.02), mean diameter variation (estimate = 0.2%, CI95 = [0.0; 0.4], P = 0.01), and mean velocity (estimate = 0.08 ms, CI95 = [0.03; 0.13], P = 0.002). Male dogs had a significantly larger mean pupil diameter than females (estimate = 1.3 mm, CI95 = [0.1; 2.5], P = 0.03). Independently of weight and sex, there was an association between mean pupil diameter and pain score: the higher the pain score, the lower the mean pupil diameter. There was a correlation between mean pupil diameter and morphine dose (ρ = -0.78, P = 0.0004). There was no significant difference in pupil diameter, velocity, and latency before and after analgesic administration. In conclusion, results do not support the use of PLR measurement by pupillometry as a pain assessment technique in hospitalized conscious dogs.

Prognostic value of lactate in cats presented in respiratory distress to the emergency room

Studies demonstrating the prognostic utility of plasma lactate concentration and lactate clearance in cats are limited. The objective of this study was to determine the prognostic utility of plasma lactate concentration upon admission and plasma lactate clearance in cats presented to the emergency room with respiratory distress attributed to underlying cardiac or respiratory disease. Additionally, we sought to determine if plasma lactate concentration on admission was significantly associated with the underlying cause of respiratory distress (cardiac vs. respiratory), type of respiratory disease, and vital parameters. Seventy-one cats presented in respiratory distress to the ER at a university teaching hospital were enrolled in this retrospective study. Admission lactate concentration was not associated with survival, duration of hospitalization, vital parameters, or underlying etiology for respiratory distress. In contrast, lactate clearance was significantly associated with survival and length of hospitalization. While a statistically significant association between lactate clearance and length of hospitalization was identified, this finding lacked clinical significance where an increase in lactate concentration by 1% was associated with an increased length of hospitalization by 11.4 min (p = 0.035). Results of this study suggest that lactate clearance may have prognostic utility in this population of cats. Further studies including the larger population of cats with underlying cardiac or respiratory disease are warranted.

Effects of time on differential leucocyte counts and biochemical parameters of ovariohysterectomy, gastrotomy and intestinal resection and anastomosis in Nigerian indigenous dogs

Differential leucocytes counts and some biochemical parameters could be affected over time by surgical procedures leading to kidney failure. Hence this study evaluates the effects of ovariohysterectomy (OVH), gastrotomy (GAT) and intestinal resection and anastomosis (ITR) on differential leucocyte counts and some biochemical parameters in Nigerian dogs. Twelve dogs of both sexes weighing 10.8±0.7 kg were randomly divided into three experimental groups of four each. The dogs were pre-treated with atropine sulphate (0.04 mg/kg), Xylazine (2 mg/kg) and propofol (6 mg/kg) parenterally, for induction and maintenance of anaesthesia. Pentazocine (3 mg/kg) was injected after surgery. Pre and post-surgery blood samples were obtained at 0, 2, 24, 48, 72, 96, 120 and 144 h respectively to determine differentials in leucocyte counts, electrolytes, lactate, blood urea nitrogen (BUN) and serum creatinine. Mathematical formulas were used to calculate plasma creatinine, creatinine clearance, plasma creatinine clearance, creatinine half- life, urine creatinine and urine volume. There were significant increases (p ≤ 0.05) in mean sodium, chloride and bicarbonate concentrations at 2, 24, 48, 72, 96 and 120 h post-surgery in group 1 and 2, while group 3 had significant decreases (p ≤ 0.05) in sodium, chloride and bicarbonate ions. Lactate value decreased significantly (p<0.05) in group 1, and increased in group 2 and 3 respectively.BUN increased significantly (p<0.05) in group 1,2 and 3.However, there were significant increases (p<0.05) in lymphocyte concentrations in group 1 and 3, respectively. Monocytes decreased significantly (p<0.05) after surgery. Conclusion: Xylazine and propofol anaesthetics cause hyperlactatemia which can be detrimental in surgical patients with co-morbidities.

Clinicopathological abnormalities associated with increased animal triage trauma score in cats presenting for vehicular trauma: 75 cases (1998-2009)

OBJECTIVE

To document the clinical and clinicopathological changes in cats presenting with vehicular trauma (VT) and to determine whether the calculated animal trauma triage (ATT) score was associated with any clinicopathological abnormalities.

DESIGN

Retrospective descriptive study conducted between 1998 and 2009.

SETTING

University veterinary teaching hospital.

ANIMALS

Seventy-five client-owned cats that presented for VT to an urban veterinary hospital.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pertinent history, physical examination findings, results of biochemical testing, and outcome were extracted from medical records. ATT score was calculated based on physical examination. Patients were classified as having either a low (<5) ATT (n = 30) or a high (≥5) ATT (n = 45) score. Male cats were overrepresented (60.0%), and a majority of cats had outdoor access (65.3%). Low PCV (P = 0.024), low total plasma protein concentration (P = 0.032), low venous blood pH (P = 0.047), high plasma lactate concentration (P = 0.047), low plasma bicarbonate concentration (P = 0.047), low base excess (P = 0.047), and high plasma glucose concentration (P = 0.047) were associated with higher ATT scores. In addition, low noninvasive blood pressure measurements (P = 0.008) were associated with higher ATT scores.

CONCLUSIONS

There was a significant association between lower PCV, lower total plasma protein concentration, lower venous blood pH, higher plasma lactate concentration, lower plasma bicarbonate concentration, lower base excess, higher whole blood glucose concentration, and lower noninvasive blood pressure and higher ATT scores at presentation in feline patients suffering from VT. Prospective evaluation of these values may prove useful in furthering understanding of the pathophysiology of trauma in cats.

Retrospective evaluation of the influence of azotemia on plasma lactate concentrations in hypotensive dogs and cats (2008-2018): 337 cases

OBJECTIVE

To evaluate the relationship between azotemia and plasma lactate concentration in hypotensive dogs and cats presented to an emergency department.

DESIGN

Retrospective case-control study.

SETTING

University veterinary teaching hospital.

ANIMALS

The electronic medical record database was searched for dogs and cats presented to the emergency department that had severe azotemia (creatinine ≥ 443.1 μmol/L [5 mg/dL]), hypotension (systolic blood pressure ≤ 90 mm Hg), and a plasma lactate measurement within 2 h of each another. Non-azotemic, normotensive dogs and cats; non-azotemic, hypotensive dogs and cats; and azotemic, normotensive dogs and cats that presented to the emergency department were used as control populations.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Severely azotemic, hypotensive dogs (n = 10) and cats (n = 63) had a lower plasma lactate than non-azotemic, hypotensive dogs and cats (P = 0.031 and P < 0.001, respectively). Median plasma lactate concentrations in hypotensive dogs (1.75 mmol/L) and cats (1.90 mmol/L) with severe azotemia were within reference intervals.

CONCLUSIONS

Hypotensive dogs and cats with severe azotemia have decreased plasma lactate concentrations as compared to hypotensive, non-azotemic dogs and cats. The median plasma lactate in azotemic, hypotensive dogs and cats was within reference intervals. This may be due to either decreased cellular production of lactate or increased excretion of lactate. Further research is needed to determine which of these mechanisms is responsible and the clinical significance of plasma lactate concentrations in azotemic, hypotensive dogs and cats.

Transvaginal uterine evisceration during labor in a Bengal queen

Case summary

A 2.5-year-old Bengal queen was admitted with a 12-h history of a mass protruding from the vulva during labor. At that time, three healthy kittens had already been delivered. Physical examination identified the mass as a portion of the uterus that was eviscerated without eversion of the mucosa. Exploratory laparotomy revealed a vaginal vault rupture with a large portion of the uterus herniated through the tear and eviscerated through the vulva. Ovariohysterectomy was performed, and a dead fetus was removed with the uterus. Reconstruction of the vaginal rupture required careful dissection and urethral catheterization. The queen recovered without complications.

Relevance and novel information

Uterine evisceration through a vaginal tear is a very rare condition that sometimes is erroneously referred to as ‘prolapse’. Uterine prolapse and uterine evisceration may have similar presenting signs; however, proper identification and surgical correction is key when the uterus is eviscerated. This case highlights the importance of differentiating these two conditions and of rapid identification and surgical intervention for successful patient survival.

Clinicopathologic abnormalities associated with increased animal triage trauma score in cats with bite wound injuries: 43 cases (1998-2009)

OBJECTIVE

To document the clinical and clinicopathologic changes in cats presenting with trauma from bite wounds, identify common abnormalities associated with bite wounds, and to determine whether the calculated animal trauma triage (ATT) score is related to any clinicopathologic abnormalities.

DESIGN

Retrospective descriptive study.

SETTING

University veterinary teaching hospital.

ANIMALS

Forty-three client-owned cats that presented for bite wounds to a large, urban, veterinary hospital between 1998 and 2009.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pertinent history, physical examination findings, results of biochemical testing, and outcome were extracted from medical records. Animal triage trauma score was calculated based on the physical examination at presentation in cats with adequate available information. Patients were classified as having either a low (<5) ATT (n = 20) or a high (≥5) ATT (n = 23) score. Male cats were overrepresented (65.1%), and a majority of cats had outdoor access (53.4%). Low venous blood pH (P = 0.047), high plasma lactate concentration (P = 0.018), and low ionized calcium concentration (P = 0.004) were associated with higher ATT scores.

CONCLUSIONS

There is a significant association between low venous blood pH, high plasma lactate concentration, and low ionized calcium concentration and higher ATT scores at presentation in cats suffering from bite wounds. Early recognition of these abnormalities may help to identify more severely injured patients.

Clinical use of plasma lactate concentration. Part 1: Physiology, pathophysiology, and measurement

OBJECTIVE

To review the current literature with respect to the physiology, pathophysiology, and measurement of lactate.

DATA SOURCES

Data were sourced from veterinary and human clinical trials, retrospective studies, experimental studies, and review articles. Articles were retrieved without date restrictions and were sourced primarily via PubMed, Scopus, and CAB Abstracts as well as by manual selection.

HUMAN AND VETERINARY DATA SYNTHESIS

Lactate is an important energy storage molecule, the production of which preserves cellular energy production and mitigates the acidosis from ATP hydrolysis. Although the most common cause of hyperlactatemia is inadequate tissue oxygen delivery, hyperlactatemia can, and does occur in the face of apparently adequate oxygen supply. At a cellular level, the pathogenesis of hyperlactatemia varies widely depending on the underlying cause. Microcirculatory dysfunction, mitochondrial dysfunction, and epinephrine-mediated stimulation of Na⁺ -K⁺ -ATPase pumps are likely important contributors to hyperlactatemia in critically ill patients. Ultimately, hyperlactatemia is a marker of altered cellular bioenergetics.

CONCLUSION

The etiology of hyperlactatemia is complex and multifactorial. Understanding the relevant pathophysiology is helpful when characterizing hyperlactatemia in clinical patients.

Survival analysis of hypotensive cats admitted to an intensive care unit with or without hyperlactatemia: 39 cases (2005-2011)

OBJECTIVE To examine the association between blood lactate concentration and survival to hospital discharge in critically ill hypotensive cats. DESIGN Retrospective case series. ANIMALS 39 cats admitted to an intensive care unit of a university veterinary hospital between January 2005 and December 2011 for which blood lactate concentration was recorded ≤ 1 hour before or after a Doppler-derived arterial blood pressure measurement ≤ 90 mm Hg (ie, hypotension) was obtained. PROCEDURES Medical records of each cat were reviewed to assess survival to hospital discharge, illness severity, duration of hospitalization, age, body weight, and PCV. Results were compared between hypotensive cats with and without hyperlactatemia (blood lactate concentration ≥ 2.5 mmol/L). RESULTS 6 of 39 (15%) hypotensive cats survived to hospital discharge. Twelve (31%) cats were normolactatemic (blood lactate concentration < 2.5 mmol/L), and 27 (69%) were hyperlactatemic. Hypotensive cats with normolactatemia had a higher blood pressure and higher survival rate than hypotensive cats with hyperlactatemia. Five-day Kaplan-Meier survival rates were 57% for normolactatemic cats and 17% for hyperlactatemic cats. Age, body weight, duration of hospitalization, PCV, and illness severity did not differ significantly between hypotensive cats with and without hyperlactatemia. CONCLUSIONS AND CLINICAL RELEVANCE Hypotensive, normolactatemic cats in an intensive care unit had a significantly greater chance of survival to hospital discharge than their hyperlactatemic counterparts. Blood lactate concentration may be a useful prognostic indicator for this patient population when used in conjunction with other clinical and laboratory findings.

Determination of reference intervals and comparison of venous blood gas parameters using standard and non-standard collection methods in 24 cats

Objectives The aim of this study was to determine in-house reference intervals (RIs) for venous blood analysis with the RAPIDPoint 500 blood gas analyser using blood gas syringes (BGSs) and to determine whether immediate analysis of venous blood collected into lithium heparin (LH) tubes can replace anaerobic blood sampling into BGSs. Methods Venous blood was collected from 24 healthy cats and directly transferred into a BGS and an LH tube. The BGS was immediately analysed on the RAPIDPoint 500 followed by the LH tube. The BGSs and LH tubes were compared using paired t-test or Wilcoxon matched-pairs signed-rank test, Bland-Altman and Passing-Bablok analysis. To assess clinical relevance, bias or percentage bias between BGSs and LH tubes was compared with the allowable total error (TEa) recommended for the respective parameter. Results Based on the values obtained from the BGSs, RIs were calculated for the evaluated parameters, including blood gases, electrolytes, glucose and lactate. Values derived from LH tubes showed no significant difference for standard bicarbonate, whole blood base excess, haematocrit, total haemoglobin, sodium, potassium, chloride, glucose and lactate, while pH, partial pressure of carbon dioxide and oxygen, actual bicarbonate, extracellular base excess, ionised calcium and anion gap were significantly different to the samples collected in BGSs ( P <0.05). Furthermore, pH, partial pressure of carbon dioxide and oxygen, extracellular base excess, ionised calcium and anion gap exceeded the recommended TEa. Conclusions and relevance Assessment of actual and standard bicarbonate, whole blood base excess, haematocrit, total haemoglobin, sodium, potassium, chloride, glucose and lactate can be made based on blood collected in LH tubes and analysed within 5 mins. For pH, partial pressure of carbon dioxide and oxygen, extracellular base excess, anion gap and ionised calcium the clinically relevant alterations have to be considered if analysed in LH tubes.

Comparison of cephalic and jugular plasma lactate concentrations in sick cats: a pilot study

OBJECTIVES

To compare plasma lactate concentration (PLC) in paired cephalic and jugular blood samples from sick cats. An additional objective was to determine whether hypotensive cats (Doppler blood pressure < 90 mm Hg) have a significant difference between cephalic and jugular PLC.

DESIGN

Prospective observational pilot study performed from December 2013 to August 2014.

SETTING

Private veterinary referral center.

ANIMALS

Twenty client-owned cats.

INTERVENTIONS

Doppler blood pressure measurements were obtained and then blood samples were collected from both a cephalic intravenous catheter at the time of placement and from a jugular vein by direct venipuncture.

MEASUREMENTS AND MAIN RESULTS

There was no significant difference between the mean cephalic PLC (2.0 mmol/L, standard deviation [SD]: 1.1, min-max: 0.6-5.3) and the mean jugular PLC (2.1 mmol/L, SD: 1.6, min-max: 0.7-7.8; P = 0.88) in this population of sick cats. Hypotensive cats also had no significant difference between the mean cephalic PLC (2.8 mmol/L, SD: 1.4, min-max: 1.6-5.3) and the mean jugular PLC (3.2 mmol/L, SD: 2.6, min-max: 0.7-7.8; P = 0.77).

CONCLUSIONS

There was not a significant difference between cephalic and jugular PLC in this population of sick cats. Further studies are needed to confirm whether cephalic and jugular PLCs may be used interchangeably in sick and hypotensive cats.

Update: Clinical Use of Plasma Lactate

Lactate is an essential, versatile metabolic fuel in cellular bioenergetics. In human emergency and critical care, lactate is used as a biomarker and therapeutic endpoint and evidence is growing in veterinary medicine supporting its clinical utility. Lactate production is a protective response providing ongoing cellular energy during tissue hypoperfusion or hypoxia and mitigating acidosis. Hence, hyperlactatemia is closely associated with disease severity but it is an epiphenomenon as the body attempts to protect itself. This article reviews lactate biochemistry, kinetics, pathophysiology, some practical aspects of measuring lactate, as well as its use in diagnosis, prognosis, and monitoring.

Hyperlactatemia and serial lactate measurements in sick cats

OBJECTIVES

To document the incidence of hyperlactatemia in sick cats hospitalized for emergency care and to evaluate the prognostic utility of serial lactate measurements in cats with hyperlactatemia.

DESIGN

Prospective observational study over a 10-month period (July 2010-May 2011).

SETTING

Private veterinary referral center with 24-hour hospital care.

ANIMALS

One hundred and twenty-three privately owned cats admitted to a private referral center.

INTERVENTIONS

Blood was collected by direct venipuncture from the jugular or medial saphenous vein at the time of hospital admission and at 6 and 24 hours following admission.

MEASUREMENTS AND MAIN RESULTS

The median plasma lactate concentration for all cats at admission (T0) was 1.89 mmol/L (17.0 mg/dL) (range: 0.3-12.48). Twenty-three percent (28/123) of cats admitted were hyperlactatemic (ie, >2.87 mmol/L; >25.86 mg/dL) upon admission. Lactate concentration at presentation and serial lactate measurements were not found to be related with survival to discharge or correlated with duration of hospitalization. The overall survival rate of all cats in this study was 81%.

CONCLUSIONS

This study demonstrated that the incidence of hyperlactatemia in sick cats being admitted for hospitalization in a private referral center was 23%, and that lactate concentration on admission and serial lactate measurements over time were not prognostic in this group of hospitalized cats. Future studies are needed to evaluate the prognostic utility of lactate and serial lactate measurements in specific disease states and in a larger population of critically ill cats.

Use of Lactate in Small Animal Clinical Practice

Lactate is a product of anaerobic metabolism. Lactate concentration in blood is used clinically as an indicator of tissue hypoperfusion and hypoxia to determine disease severity, assess response to therapy, and predict outcome. This article reviews lactate physiology, sample collection and processing, and interpretation of lactate concentration in clinical practice.

Point of Care Measurement of Lactate

Lactate is generated as a consequence of anaerobic glycolysis by all tissues of the body. Increased l-lactate, the isoform produced by most mammals, reflects increased anaerobic metabolism secondary to tissue hypoperfusion or tissue hypoxia in most clinical situations, and is called type A lactic acidosis. The utility of lactate measurement and serial lactate monitoring in veterinary patients has been demonstrated in multiple studies. Blood lactate concentration is significantly elevated in many disease processes including septic peritonitis, immune-mediated hemolytic anemia, Babesiosis, trauma, gastric dilation and volvulus, and intracranial disease. Lactate clearance can be used to assess response to fluid therapy, cardiovascular therapeutics, and blood product transfusion in patients affected by type A lactic acidosis. Lactate concentration in peritoneal, pericardial, and synovial fluid can also be used as a diagnostic tool. Point of care analyzers such as the Lactate Pro, Lactate Scout, Accutrend, iSTAT, and Lactate Plus have been shown to be accurate lactate measurement instruments in small animal patients.

Plasma lactate concentrations and comparison of two point-of-care lactate analyzers to a laboratory analyzer in a population of healthy cats

OBJECTIVE

To establish a reference interval for plasma lactate in a population of healthy adult cats on a laboratory analyzer (Nova Biomedical Critical Care Xpress [CCX]) and 2 commercially available point-of-care (POC) analyzers (Abbott i-STAT [i-STAT] and Nova Biomedical Lactate Plus [LP]), and to compare the level of agreement of lactate measurement between the laboratory analyzer and POC analyzers.

DESIGN

Prospective observational study.

SETTING

University veterinary teaching hospital.

ANIMALS

Forty-seven healthy adult cats.

INTERVENTIONS

Jugular phlebotomy.

MEASUREMENTS AND MAIN RESULTS

In this population, plasma lactate reference interval was 0.67-5.44 mmol/L for the CCX, 0.65-5.16 mmol/L for the i-STAT, and 0.68-4.39 mmol/L for the LP. Comparisons were made between lactate measurements on 2 point-of-care analyzers and the laboratory analyzer using the Bland-Altman method. For the comparison of CCX and i-STAT, the bias was -0.10 mmol/L; for the CCX and LP, the bias was -0.24 mmol/L.

CONCLUSIONS

Measurements of plasma lactate in cats using the i-STAT showed acceptable agreement with the CCX. The LP showed weaker agreement. However, both POC analyzers are suitable for measurement of lactate in cats, provided results from different POC analyzers are not directly compared. This study identified a larger reference interval for plasma lactate concentration in cats than what has been previously reported.

Perioperative Acid-Base and Electrolyte Disturbances

Obtaining and interpreting blood gas and electrolyte levels is essential in the management of perioperative veterinary patients. Metabolic and electrolyte alterations are common in critically ill surgical patients, and can lead to alterations in cardiovascular function, neurologic status, respiratory function, and even response to various drug therapies. Several common perioperative conditions are discussed in this article, including metabolic disturbances, electrolyte abnormalities (hyponatremia and hypernatremia, hyperkalemia), and respiratory abnormalities.

Practical acid-base in veterinary patients

Acid-base abnormalities are common in critically ill veterinary patients. Rapid recognition of disturbances can be helpful in identifying the underlying cause of the patient's clinical signs, directing diagnostics, and monitoring response to therapy. If acid-base disturbances are left unidentified and untreated, severe physiologic consequences can result, including cardiovascular and neurologic dysfunction, protein and enzyme dysfunction, and electrolyte derangements. Treatment of acid-base disorders is aimed at correcting the underlying disease process.